Low-alcohol yeast process



Patented Mar. 20, i 1923..

UNHTED FRTEIDETCH HAYD UCK, F WILIEERSDORF, GERTQANSZ, ASSIGNOB TQ v v meant; ES rent enema- TEE FEiEISGH- 111m COMPANY 5- 015 NEW YUJRK, N. Y" A COBJPOTION 0K UEZIEG'.

now-atooiaor YEAST recon-sa Ho Drawing.

Application filled ectober 30, 1920. Serial 130. 420,834.

(GEAKTTED UNDER THE PROVISIQNS @lFTHlE ACT 01E MAR-0H 3,1921, 41 STAT. L. 1813.)

To all whom it may concern:

Be it known that T, Fmnnm'orr HAYDUCK, a. citizen of Germany, residln dorf, Germany, have invente certain new and useful Improvements in Low-Alcohol Yeast Processes (for which Isfiphcation for patent was filed in Germany I in is a'specification.

his invention relates to a-processfor themanufactureof An object of this invention is to provide an improved procedure for the commercial production of yeast in a convenle'nt and economical manner.

In my co-pending applications,Serial Nos. a20.832 and 420,833, filed October 30, 1920, which correspond to the German Patents Nos. 300.682, and 303,222, processes are disclosed wherein the seed east is suspended either in water or in a dilute nutrientsolution which is aerated and to which a yeast nutrient solution is substantially continuously added at a rate such that all of the yeast nutrients, and substantially all of the alcohol which'may be formed, are assimilated by the yeast. j v

The worts which may be used in these processes may be of any type suitable for yeast propagation, as for example, the usual 12 Balling wort referred to in my first mentioned co-pending application No; 420,- 832, or the artificially prepared yeast nutrient solution comprising essentially sugar material 'and yeast nourishing inorganic salts, wherein the sugar is present to an amount yeast nutrient salts may be present up to an amount of one-half the sugar content, as described in my co-pending application Serial No. 420,833. As an example of the last mentioned nutrient solution, the following is given:

Sugar 100 parts, ammonium sulphate 40 parts, acid potassium phosphate 9 parts, magnesium sulphate 1 part, calcium carbonate forneutralization about 30 parts; or

at Wilmersarch 31, 1915," Patent No."303,221), oil which the ttollow co'mparatively little of approximately 10%, and the Molasses '(containin 50% sugar) 100 parts, ammonium sulp-ate 10' parts, super-- phosphate having 18% Water soluble phosphoric acid 10 parts, magnesium sulphate 0.5 parts, calcium carbonate for neutralization, about 4 parts.

In a certain aspect of this invention therefore, the abovedescribed process 0 manufacture might likewise be considered to be terminated in any portion'of the wort at this time so that without injury to the seeding of the wort, parts of the propagating liquid containing yeast might "be constantly withdrawn. I have discovered that as-a result of this, it is-possible to carry on a process of uninterrupted operations, which ma be called a continuous process.

s an example of the method of carrying out such a process,'the' following is given:

A high or deep, rather-than broad, fermenting vat is selected in which there is arranged below the air supply pipin an easily adjustable fiowing-oii-dev1ce,-w ich as is usual. leads to the separating centrifugal. The seed yeast is suspended in this vat in a liquid which should be nontoxic to yeast, for example, either-in a small depth of water or of a diluted portion of the nutrient solution which is to be used. The suspension is then aerated and the addition of the remainder of the nutrient solution is begun in a substantially continuous manner and at a rate such that substantially all of the alcohol which may be formed is assimi lated by the yeast. As soon as a suflicient amount of propagating solution and yeast has accumulated, for example,. as soon as the fermenting vat is nearly filled up, the discharge valve is opened and is so adjusted that the liquid containin the yeast is discharged at substantially t e same rate that the fresh nutrient solution is being admitted at the'top of the vat. The liquid containing the yeast which is drawn off, is either led to the centrifugals or to other suitable yeast separating means, and the separated yeast is cooled, washed, and pressed in the usual manner.

llt is known from the German patent to Rainier, No; 10135, that yeast may be grown in a dilute nutrient solution to which solutions of sugar and peptone are added separately, when required by the yeast, the

at 2 1, as is'deterniine'd by suitable tests, the

. peptone being added either tractional'l or liquid thus separated rom' h'eyas't being a Patent, is

contiusly, and the sugar being a dad fractionally at certain intervals'. In this process, the yeast is removed at successive intervals, either by skimming-br ity allowing it to settle and decantin the liquid, the

used aszth seedeolliquid for gturther propagation. he manner in w 10h this 1s carried orig-necessitates the interruption of ermpaast p r t l, a

in, coiitrast to the Rainier. processfthe present process efiects the, withdrawal of the yeast continuously and at substantially I the same rate as that at whichthe nutrient supply is added, so thatthe volume of propagating liquid N is ,maintained substantially constant and the yeast-containing solution is being constantly conducted to the. centrifugals, thereby assuring a continuous outpa -yea Although, the worts described n my above mentioned oo-pending applications are of.ravi,tie s approximating 12 Balling, it will be seen that W,or,ts of other concentrations might be used, provided therate of addition theretofbe controlled so that the concentration of the propagating liquid would not rise above the ,point at which substantially all the alcohol which might be formed would be assimilated by the yeast.

Having described my invention, what 1 claim as new and desire to secure by Letters 1. A continuous process of propagating yeast which comprises suspending seed yeast ina relatively small depth of a non-toxic liquid in a relatively deep vat, aerating the liquid, adding dnr'ingthe period of propagailOIlflty: east nutrient solution and, as soon as a .su cient quantity of propagating solution has accumulated, simultaneously withdrawing the yeast containing solution.

v2. A continuous process otpropagating yeast which comprises preparing a relatively- ..concentrated yeast nutrient'solution, withdrawing such a portion, thereof into a relatively deep vat that when highly diluted it wouldfill a relatively small depth, dilutingthe portion, initiating propagation of yeast being added.

insane? therein antestem, sttaaaaanyeenemous'l'y ad mg the more concentratednutrient solution during the period of propagation,

and as. soon. as a suflicient quantity of 'pro-' pagatirrgasolution has. accumulated, withdrawingthe ast containing solution from e "the vat-at substantially the same rate that the fresh nutrient solution is added.

3. A cdiitinu'ous process of ropagatin yeast with a relatively low yield oi; alcohol which comprises preparing "a relatively concentrated yeast nutrient solution, withdrawingsuch a. portion thereof into a relatively deep vat that when hi hly diluted it would fill a relatively small epth, diluting the portion, initiating propagation of yeast therein with aeration, adding during the period of propagation the nutrient solution of higher concentration at a rate such that the concentration of the diluted portion does not rise above that at which substantially all alcohol which may be formed will be assimilated by the yeast, and as soon as a suflicient quantity of propagating solution has accumulated, Withdrawing the yeast containing solution' from the vat at substantially the samerate that the fresh nutrient solutlon is being added 4.; A continuous process of propa ating yeast with a relatively low yield of a cohol which comprises preparing a relatively conce'ntrated yeast nutrient solution, withdrawing and highly diluting such a portion thereofthat it would fill a relatively small depth in a relatively deep vat, initiating the propagationof; east therein, substantially continuously," ad ing during the period of propagation the nutrient solution of higher concentration at. a rate such that the concentration of the diluted portion does not rise above that atwhich substantially all alcohol which maybe formed will be assimilated by the yeast, and as soon as a sufiicient quantity of propagating solution has accumulated, withdrawing the yeast containing solution from the vat at substantially the same rate that the fresh nutrient solution is lln'testi'mony whereof, I have affixed my signature.

' "i rti nnnion HAYDUCK. 

